Apparatus and methods for material capture and removal

ABSTRACT

Catheters, kits, and methods are provided for removing material from a body lumen. The catheters and methods may be used in a variety of body lumens, including but not limited to coronary and other arteries. In general, the catheter has a cutting element that cuts material while the material is engaged by a material capture device on the catheter body. Preferably, the material capture device tensions the material during cutting, which reduces the amount of cutting force required. The material capture device typically follows a path that draws material into the catheter body. Preferably, but not necessarily, the material capture device may be arranged on the catheter body to advance along a path outwardly from the catheter body into the material and then inwardly towards the catheter body to tension the material. The cutting element on the catheter body moves between a first position and a second position to cut the material while in tension.

BACKGROUND OF THE INVENTION

[0001] The present invention relates generally to apparatus and methodsfor removing occluding materials from body lumens. More particularly,the present invention relates to the construction and use of atherectomycatheters for excising atheroma and other materials from blood vessels.

[0002] Cardiovascular disease frequently arises from the accumulation ofatheromatous material on the inner walls of vascular lumens,particularly arterial lumens of the coronary and other vasculature,resulting in a condition known as atherosclerosis. Atherosclerosisoccurs naturally as a result of aging, but may also be aggravated byfactors such as diet, hypertension, heredity, vascular injury, and thelike. Atheromatous and other vascular deposits restrict blood flow andcan cause ischemia which, in acute cases, can result in myocardialinfarction. Atheromatous deposits can have widely varying properties,with some deposits being relatively soft and others being fibrous and/orcalcified. In the latter case, the deposits are frequently referred toas plaque.

[0003] Atherosclerosis can be treated in a variety of ways, includingdrugs, bypass surgery, and a variety of catheter-based approaches whichrely on intravascular widening or removal of the atheromatous or othermaterial occluding a blood vessel. Of particular interest to the presentinvention, a variety of methods for cutting or dislodging material andremoving such material from the blood vessel have been proposed,generally being referred to as atherectomy procedures. Atherectomycatheters intended to excise material from the blood vessel lumengenerally employ a rotatable and/or axially translatable cutting bladewhich can be advanced into or past the occlusive material in order tocut and separate such material from the blood vessel lumen. Inparticular, side-cutting atherectomy catheters generally employ ahousing having an aperture on one side, a blade which is rotated ortranslated by the aperture, and a balloon or other deflecting structureto urge the aperture against the material to be removed.

[0004] Although atherectomy catheters have proven to be very successfulin treating many types of atherosclerosis, some catheter designs sufferfrom certain limitations. For example, many side-cutting atherectomycatheters have difficulty in capturing occluding material in the cuttingaperture. To facilitate material capture, the cutting aperture isfrequently elongated. Although improving material capture, suchlengthening makes it more difficult to introduce the distal end of thecatheter through torturous regions of the vasculature. Additionally, itis often difficult for conventional atherectomy cutters to apply therequisite pressure to cut off the targeted material. When higherpressures are applied, damage to the artery (barotrauma) can occur. Highpressures can also compress plaque, subsequently reducing the cutter'sability to capture the occlusive material. This decreases theeffectiveness of these cutters and limits the cutter and catheterdesigns.

[0005] For these reasons, it is desired to provide atherectomy catheterswhich can access small, tortuous regions of the vasculature and whichcan remove atheromatous and other occluding materials from within bloodvessels in a controlled fashion with minimum risk of injuring the bloodvessel wall. In particular, it is desired to provide atherectomycatheters which can facilitate capturing of occlusive material. It wouldalso be particularly desirable to decrease the amount of force requiredto cut off occlusive material from the body. At least some of theseobjectives will be met by the catheter and method of the presentinvention described hereinafter and in the claims.

SUMMARY OF THE INVENTION

[0006] The present invention provides catheters, kits, and methods forremoving material from a body lumen. The catheters and methods of thepresent invention are for use in a variety of body lumens, including butnot limited to intravascular lumens such as the coronary artery andother blood vessels. In general, the catheter of the present inventionhas a cutting element that cuts material engaged by a material capturedevice on the catheter body. Preferably, the material capture devicetensions the material during cutting, which reduces the amount ofcutting force required. The material capture device typically follows apath that draws material into the catheter body. Preferably, but notnecessarily, the material capture device is arranged on the catheterbody to advance along a path outwardly from the catheter body into thematerial and then inwardly towards the catheter body to tension thematerial. In some embodiments, the material capture device may extend inan outwardly direction but not beyond the outer diameter of the catheterbody. The cutting element on the catheter body moves between a firstposition and a second position to cut the material while in tension,where motion of the cutting element urges the material capture device todraw cut material into the catheter body.

[0007] Desirably, the blade or blades of the catheter will be actuablewith the application of reasonable mechanical forces which are capableof being transmitted along even rather lengthy catheters. Furtherdesirably, the catheters will be suitable for directional removal ofoccluding material and may include mechanisms for engaging cuttingblades against selected portions of a vascular wall. Optionally, theengaging mechanisms should permit blood perfusion during performance ofan atherectomy procedure.

[0008] In one embodiment, the catheter of the present invention uses amaterial capture device in the form of a material capture needle. Theneedle will be deployed in a radially outward direction from thecatheter body. Preferably, but not necessarily, the needle will capturematerial while the catheter remains stationary. Some embodiments may usea plurality of material capture needles. The material capture needle mayfollow a path outwardly from the catheter body in various manners. Inone embodiment, the needle has a portion that advances through anelongate slot on the catheter body to move the needle along a pathoutwardly from the catheter body. Another embodiment uses a curvedneedle rotatably mounted about a pivot pin. As the needle is rotated, itwill protrude outwardly from the catheter body. A preferred embodimentuses a needle having a bias element which urges the needle outwardlywhen the catheter is in position. Typically, a material cutting elementwill engage the material that has been captured and sheer off thematerial into the catheter.

[0009] In a further embodiment, a material capture device of the presentinvention uses a penetrating member mounted to extend through anaperture on the catheter body to penetrate material in advance of thecutting blade and to draw material into the catheter body as the cuttingblade is advanced past the aperture. The penetrating member is rotatablymounted to the slidable cutting blade on the catheter body. A camsurface on the catheter body engages a surface of the penetrating memberto guide the member along a path to engage the material and draw thematerial into the catheter body. In a still further embodiment, anabutment or raised portion on the catheter body is mounted to engage oneend of the penetrating member. This contact caused the penetratingmember to rotate about its pivot point on the cutting blade and thusengage material and draw material into the catheter body.

[0010] In another aspect of the present invention, a method is providedfor excising occlusive material from within a body lumen. The methodinvolves engaging the occlusive material with a material capture deviceon a catheter body. The material is drawn in a radially inward directionby the device to tension the material to be cut. A blade is advancedthrough the tensioned material to sever the material from the bodylumen. As mentioned previously, tensioning the material reduces theamount of cutting force required. The tensioning of the occlusivematerial may also comprise moving the material capture device towards acatheter body while the material capture device is in contact with theocclusive material. Typically, the engaging and tensioning steps mayalso be performed with a single motion by the user to facilitatecutting.

[0011] In a still further aspect, kits according to the presentinvention will comprise a catheter having a material capture device. Thekits will further include instructions for use setting forth a method asdescribed above. Optionally, the kits will further include packagingsuitable for containing the catheter and the instructions for use.Exemplary containers include pouches, trays, boxes, tubes, and the like.The instructions for use may be provided on a separate sheet of paper orother medium. Optionally, the instructions may be printed in whole or inpart on the packaging. Usually, at least the catheter will be providedin a sterilized condition. Other kit components, such as a guidewire,may also be included.

[0012] A further understanding of the nature and advantages of theinvention will become apparent by reference to the remaining portions ofthe specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013]FIG. 1 is a perspective view of an atherectomy catheterconstructed in accordance with the principles of the present invention.

[0014] FIGS. 2-4 show various embodiments of a material capture deviceand a material cutting element according to the present invention.

[0015] FIGS. 5A-5C illustrate a material cutting sequence using oneembodiment of a material capture device and material cutting elementaccording to the present invention.

[0016] FIGS. 6A-6B show cross-sectional views of a further embodiment ofa material capture device and material cutting element.

[0017] FIGS. 7-8 show still further embodiments of a material capturedevice and material cutting element.

[0018] FIGS. 9-11 show cross-sectional views of a preferred embodimentof the material capture device;

[0019]FIGS. 12, 13, 14, 14A-C, and 15 show alternative embodiments ofthe device show in FIGS. 9-11.

[0020] FIGS. 16-18 depict various embodiments of a cam surface accordingto the present invention.

[0021] FIGS. 19-22 are cross-sectional views of a telescoping cutterhaving a material capture device according to the present invention.

[0022] FIGS. 23-24 show a still further embodiment of the materialcapture device.

[0023]FIG. 25 shows a kit according to the present invention.

[0024]FIGS. 26 and 27 illustrate a catheter having material capturedevices and material cutting elements oriented at various angles on thecatheter body.

[0025]FIG. 28 shows a preferred embodiment of the present invention foruse with a material imaging device according to the present invention.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

[0026] The present invention provides devices, methods, and kits for usein removing material from a body lumen. The present invention may beused in a variety of body lumens, including but not limited to coronaryand other arteries. Advantageously, the present invention reduces theamount of force required to cut material and facilitates materialcapture into apertures of the catheter.

[0027] Apparatus according to the present invention will comprisecatheters having catheter bodies adapted for intraluminal introductionto the target body lumen. The dimensions and other physicalcharacteristics of the catheter bodies will vary significantly dependingon the body lumen which is to be accessed. In the exemplary case ofatherectomy catheters intended for intravascular introduction, thecatheter bodies will typically be very flexible and suitable forintroduction over a guidewire to a target site within the vasculature.In particular, catheters can be intended for “over-the-wire”introduction when a guidewire lumen extends fully through the catheterbody or for “rapid exchange” introduction where the guidewire lumenextends only through a distal portion of the catheter body.

[0028] Catheter bodies intended for intravascular introduction willtypically have a length in the range from 50 cm to 200 cm and an outerdiameter in the range from 1 French (0.33 mm; Fr.) to 12 Fr., usuallyfrom 3 Fr. to 9 Fr. In the case of coronary catheters, the length istypically in the range from 125 to 200 cm, the diameter is preferablybelow 8 Fr., more preferably below 7 Fr., and most preferably in therange from 2 Fr. to 7 Fr. Catheter bodies will typically be composed ofan organic polymer which is fabricated by conventional extrusiontechniques. Suitable polymers include polyvinylchloride, polyurethanes,polyesters, polytetrafluoroethylenes (PTFE), silicone rubbers, naturalrubbers, and the like. Optionally, the catheter body may be reinforcedwith braid, helical wires, axial filaments, or the like, in order toincrease rotational strength, column strength, toughness, pushability,and the like. Suitable catheter bodies may be formed by extrusion, withone or more lumens being provided when desired. The catheter diametercan be modified by heat expansion and shrinkage using conventionaltechniques. The resulting catheters will thus be suitable forintroduction to the vascular system, often the coronary arteries, byconventional techniques.

[0029] The cutting blades used in the present invention will usually beformed from a metal, but could also be formed from hard plastics,ceramics, or composites of two or more materials, which can be honed orotherwise formed into the desired cutting edge. In the exemplaryembodiments, the cutting blades are formed as coaxial tubular bladeswith the cutting edges defined in aligned apertures therein. It will beappreciated that the present invention is not limited to such preferredcutting blade assemblies, in a variety of other designs, such as the useof wiper blades, scissor blades or the like. Optionally, the cuttingedge of either or both the blades may be hardened, e.g., by applicationof a coating. A preferred coating material is titanium nitride,available from Brycoat, Inc., which may be applied according tomanufacturer's instructions.

[0030] Referring now to FIG. 1, a catheter 10 constructed in accordancewith the principles of the present invention comprises a catheter body12 having a proximal end 14 and a distal end 16. A cutting mechanism 18comprises an outer cutter 20, an inner cutter 22 is attached to thedistal end of the catheter body 12, and a needle 23 as a materialcapture device. An atraumatic tip 24 is attached to the distal end ofthe outer cutter 20, and a guidewire lumen 25 extends through the entirecatheter body, cutting mechanism 18, and terminates in port 25 at thedistal tip of tip section 24. A proximal hub 30 is attached to theproximal end of catheter body 12 and comprises a perfusion/aspirationconnector 32, a guidewire connector 34, and a slider 36. The slider 36is attached to the proximal end of an actuator rod 37 which extends fromthe hub 30 through the lumen of catheter body 12 into the cuttingmechanism 18 where it is attached at a proximal end of the inner cutter22. In this way, manual actuation of slider 36 in the direction of arrow38 moves inner cutter 22 in the direction of arrow 40.

[0031] Referring to FIGS. 2A and 2B, this embodiment of the catheter 10uses the material capture needle 23 to capture the material and tensionit towards the cutters 20 and 22. The material capture needle 23 followsa path where the material capture needle extends outwardly from thecatheter body and moves inwardly towards the catheter body to tensionthe material. In this embodiment, when the material capture needle 23 isdeployed, it angles out from the aperture 42 and a portion of thematerial capture needle typically runs parallel to the window with thesharpened tip located near the proximal end of the aperture. The innercutter or cutting element 22 is reciprocated to open and close theaperture 42 formed in the wall of the catheter body 12. Movement of theinner cutter 22 also controls the deployment of the material captureneedle. When the inner cutter 22 opens the aperture 42, the materialcapture needle 23 is biased outwardly from the catheter body 12. Thematerial capture needle 23 is preferably spring-loaded, where in itsresting condition, the material capture needle extends outwardly fromthe catheter body 12. The material capture needle 23 is otherwiseconstrained within the catheter body 12 when the inner cutter 22 closesaperture 42. The material capture needle 23 may be made of a variety ofmaterials such as stainless steel or a superelastic material.

[0032] With the material capture needle 23 deployed as shown in FIG. 2B,the material capture needle may penetrate into the material when thecatheter body 12 is pulled in the proximal direction. The inner cutter22 is then closed, as indicated by arrow 40, to push the materialcapture needle 23 towards the catheter body 12 as indicated by arrow 44.Preferably, closing of cutter 22 will tension the material and draw itinto the catheter body 12 when the cutters 20 and 22 will shear off thematerial. It is also preferred that the inner cutter 22, upon finishingthe closing motion, will wipe the piece of cut-off material off thematerial capture needle 23 and into the catheter for storage. Thematerial capture needle 23 and cutting mechanism 18 may then be readiedto make a subsequent cut. The material capture needle 23 typically has adiameter between about 0.1 to 0.5 mm, preferably 0.2 to 0.3 mm, with alength between about 1 to 5 mm, preferably 3 to 4 mm.

[0033] Referring to FIGS. 3-4, a variety of catheter embodiments mayincorporate a needle as a material capture device. Like the catheter ofFIG. 2, these catheters rely on the motion of a cutter to controlpositioning of the material capture needle during cutting. The FIGS.3A-3B show the distal portion of a catheter 50 having an outer cutter 52which reciprocates to control the deployment of the material captureneedle 54. Additionally, in this embodiment, the material capture needle54 is deployed to have a forward pointing sharpened tip. With thematerial capture needle 54 deployed, the catheter 50 would be pushedforward as indicated by arrow 56 to penetrate target material T. Thecatheter 50 may also incorporate a ski mechanism 58 to urge the cuttingside of the catheter radially against the target material T. Such a skimechanism is described in detail in commonly assigned, copending U.S.patent application Ser. No. 08/982,231 (Attorney Docket No.18489-000200) filed Dec. 17, 1997, the full disclosure of which isincorporated herein by reference. All of the catheter structures hereinmay optionally employ such mechanisms.

[0034]FIGS. 4A and 4B show a catheter 70 having a telescoping cutter 72for use with a material capture needle 74. The telescoping cutter 72 isused to decrease the rigid length of the catheter 70 and may be used tocreate a larger window or aperture 76 for removing greater amounts ofmaterial. As the telescoping cutter 72 is drawn proximally, the materialcapture needle 74 will be pushed into the aperture 76 as indicated byarrow 78, along with material attached to the material capture needle.As seen in FIG. 4B, the material capture device 74 may also include oneor more barbs 79 which keep the material from sliding off once it isexcised.

[0035] The catheter 70 is quite useful and an improvement overconventional atherectomy catheters even without incorporation of thematerial capture needle 74. The decrease in the rigid length of thedistal portion of catheter 70 is a significant advantage, particularlywhen the catheter is introduced to the highly tortuous regions of thecoronary vasculature. Once at a desired location, however, the rigidcutter portion of the catheter can be extended in length by 50% or more,with a theoretical limit of 100% for a two-portion telescoping region.In the illustrated embodiment, the cutting aperture 76 is defined onlyon one of the cutter blades. In other embodiments, it will possible todefine the aperture on both of the cutting blades and/or in a variety ofconfigurations. While the cutting blades will preferably employ thecutting edges at each end, the advantages of the telescoping cutter canbe enjoyed even without the cutting edges.

[0036] Referring now to FIGS. 5A-5C, another embodiment of anatherectomy catheter 100 uses a material capture needle 102 whichrotates about a pivot pin 104. As indicated by arrow 106 in FIG. 5A, thematerial capture needle 102 will rotate upward as the drawbar 108 ispulled proximally. As seen in the cross-section of FIG. 5B, the drawbar108 is coupled to slider 110 which has cutting blade 112. A cam 106about the pivot pin 104 will pull against the material capture needle102 as drawbar 108 is moved. The drawbar 108 will be retracted until theblade 112, as shown in FIG. 5C, has sheared off any material captured bythe material capture needle 102.

[0037]FIGS. 6A and 6B show a catheter embodiment similar to that ofFIGS. 5A-5C. The material capture needle 120 of FIG. 6A rotates about apivot 122 to engage material M to be excised from the luminal wall. Theneedle actuator for this embodiment differs from that of catheter 100.The material capture needle 120 of the present embodiment sits betweentabs 124 and 126 which are attached to the drawbar 130. The drawbar 130rotates the needle 120 while pulling on slider 132 having blade 134. Ofcourse, it should be understood that the motion of the pivoting materialcapture needle 120 may be dependent or independent of the motion of thecutting element or blade 134. The material capture needle 120 may alsobe constructed of existing devices such as a suture needle used inprocedures such as coronary anastomoses.

[0038]FIG. 7 shows a material capture needle 150 mounted on a base 152which slides within elongate slots or grooves 154 and 156. The slots 154and 156 guide the needle 150 along a path that carries the needleoutward and then inwardly towards the catheter body 158 after the needlehas engaged the catheter body. The inner cutter 160 has a cut-out 162which holds the base 152 as the cutter is moved with the materialcapture needle 150. The base may move vertically within the cut-out 162to follow the slots 154 and 156.

[0039] In a still further embodiment of the cutting mechanism, FIG. 8shows a cutter 170 which is controlled by a drawbar 172 which isseparate from the material capture needles 180 and drawbar 182. Thematerial capture needles 180 continue to pivot as indicated by arrows184. Pulling of the cutter drawbar 172 will reciprocate the cutter 170without interacting with the positioning of the material capture needle180. Such separate control may be desirable in particular situationswhere the timing of the engagement of the material capture needle 180and the cutter 170 must be more accurately controlled.

[0040] Referring now to FIG. 9, a preferred embodiment of the presentinvention having a material capture device will now be described infurther detail. FIG. 9 shows an inner cutter 200 mounted coaxiallywithin an outer cutter 202 and in a fully distal position to open thewindow 204. The material capture device in this embodiment comprises apenetrating member 206 and a cam surface 208. The penetrating member 206is pivotably mounted on the inner cutter about a pivot pin 210. Thepenetrating member 206 has a curved surface 212 that is designed toslide over the cam surface 208. The curved surface 212 is typically alower or underside surface of the penetrating member 206. As the innercutter 200 is advanced during the cutting motion, the cam surface 208will guide the penetrating member 206 in a radially outward directionalong a path that brings the member into engagement with targetedmaterial. By varying the shape of the curved surface 212 and the heightof the cam surface 208, the penetrating member 206 may have a variety ofmaterial-engaging positions, e.g., where the sharpened tip 214 extendsradially beyond the outer diameter of the outer cutter 202, where thesharpened tip 214 is radially aligned with the outer diameter of theouter cutter or the inner cutter 200, or where the tip 214 is within theinner cutter. It should be understood that the curved surface 212 may bealso contain longitudinal grooves and be contoured as desired to bestfollow and maintain contact with the cam surface 208 during the cuttingmotion. As shown in FIG. 9, the penetrating member 206 includes a lowerprotrusion 216 which helps move tissue proximally away from the cuttersafter the tissue has been excised.

[0041] Referring now to FIG. 10, a drive wire 220 mounted within a drivetube 222 is used to move the inner cutter 200 from a first, openposition to a second, closed position. Of course, other push/pullelements or separate push elements and pull elements may be used tocontrol the movement of the inner cutter 200. The drive wire 220 may bemade of material such as stainless steel or nickel titanium. The drivetube 222 may also be made of a variety of materials such as a polymerlike polyimide, polyurethane, or polyethylene or a flexible metal suchas nickel titanium. The drive tube 222 may also be made from a compositeof metal and polymer, or a metal that has material selectively removedto increase its flexibility. Further details of the drive tube can befound in commonly assigned, copending U.S. patent application Ser. No.08/982,231 (Attorney Docket No. 18489-000200US), filed on Dec. 17, 1997,the full disclosure of which is incorporated herein by reference.

[0042] As seen in FIGS. 10 and 11, the cam surface 208 is fixedlysecured to the outer cutter 202 and remains stationary relative to thepenetrating member 206 during the cutting motion. The inner cutter 200typically includes a slot or cut-out portion to accommodate the camsurface 208. Movement of the inner cutter 200 brings the sharpened end214 into contact with target material which is pushed towards the firstblade 224 (FIG. 10). Referring now to FIG. 11 as the window 204 isclosed, a second blade 226 on the inner cutter 200 will complete thecutting motion by shearing off the material against the first blade 224.The cam surface 208 will push against the lower surface 212 of thepenetrating member 206 and force the sharpened tip 214 of thepenetrating member to retract into the inner cutter as shown in FIG. 11.

[0043] Referring now to FIGS. 12-14, other embodiments of thepenetrating member, cam surface, and inner cutter will now be described.FIG. 12 shows an embodiment of the penetrating member 230 where themember has a more aggressively designed sharpened tip 232. Theadditional length of the tip 232 allows the penetrating member 230 toengage materials further away from the outer cutter 202. The lowersurface 234 of the penetrating member 230 includes a recessed portion236 that allows the penetrating member to be retracted into the outercutter 202 when the inner cutter 200 is in its distal most position.

[0044]FIG. 13 shows a material capture device where the sharpened tip240 of the penetrating member 242 is even with the outer diameter of theouter cutter 202 when the penetrating member is in its tissue-engagingposition. The cam surface 244 has a decreased height and the location ofthe pivot pin 246 has also been lowered to change the position of thesharpened tip 240. The extension distance may vary depending on thedesired function of the cutter. For example, the extension distance ofthe penetrating member (where the outer edge of the inner cutter is0.000) may range between about-0.05 to 0.10 inches (as shown inphantom), preferably between about 0.00 to 0.04 inches, and mostpreferably between about 0.01 to 0.02 inches for a 0.100 maximumdiameter cutter. The length of the sharpened tip 240 may also be used tochange the maximum extension distance of the material capture device.

[0045]FIG. 14 shows an embodiment of the penetrating member 250 usedwith a reduced length inner cutter 252. Using a shorter inner cutter 252can reduce the rigid length of the catheter and improve tracking of thecatheter through tortuous vasculature. Unlike the inner cutters shown inFIGS. 9-11, the inner cutter 252 in FIG. 14 has the side-openingaperture 254 located at the proximal end of the cutter. In otherembodiments, this side-opening aperture is located away from the ends ofthe cutter. Moving the aperture 254 to the end of the cutter 252 allowsthe reduction in rigid length. In this embodiment, the drive wire 220 isrepositioned to be on the lower surface of the inner cutter 252.

[0046] The embodiments of FIGS. 12-14 may further be provided withpositioner wires as shown in FIGS. 14A-14C. The cutter mechanism 500comprises a penetrating member 502, an inner cutter 504, an outertubular cutter 506, and a pair of positioner wires 510 (only one ofwhich is visible in the figures). The inner cutter 504 is shown in ifits closed (fully proximally advanced) configuration in FIG. 14A. Thepenetrating member 502 is fully radially retracted within the cutterassembly, and the positioning wires are also fully retracted.

[0047] The positioning wires 510 form from a resilient material,typically stainless steel ribbon or a shape memory alloy ribbon, such asnitinol. The proximal ends of each wire are attached in slots formednear the proximal end of the outer tubular cutter 506 and extendinwardly through openings (not shown) so that their distal ends extendradially inwardly into the interior of the outer tubular cutter, asshown in the left-hand side of FIG. 14A. With the inner cutter 504closed, as shown in FIG. 14A, the cutter mechanism 500 can be advancedthrough the vasculature with a minimum profile, i.e., neither thetissue-penetrating member 502 nor the positioner wires 510 extend outfrom the cutter mechanism.

[0048] Once positioned at the treatment location, the inner cuttingblade 504 may be distally retracted, both opening a cutter window 514and causing the cam surface 518 on the penetrating member 502 to engagea cam element 520, causing the penetrating tip of the penetratingelement 502 to emerge through the cutter window 514 as generallydescribed with the embodiments of FIGS. 12-14. Cutter mechanism 500differs from the earlier embodiments in that a lower portion of theinner cutter 504 engages the curved distal ends 522 of the positionerwires 510, as best seen in FIG. 14B. In particular, as the inner cutter504 moves in a distal direction, (i.e., toward the left in FIGS.14A-14C), it depresses the curved ends 522, causing the main body of thepositioner wires 510 to emerge from the outer cutter 506, as indicatedat 530 in FIG. 14B. As the inner cutter 504 moves further in the distaldirection, the positioner wires 510 are deployed fully outwardly, asbest shown in FIG. 14C. The cutter window 514 is fully opened and thepenetrating member 502 again retracted within the cutter mechanism 500.With the positioner wires 510 fully deployed, the penetrating member 502of the cutter mechanism is disposed to penetrate into target tissue asthe inner cutter member 504 is closed in the proximal direction.Preferably, the positioner wires 510 will apply a very low amount offorce against the artery wall since the penetrating member 502 will beable to quickly engage and capture the tissue to be cut by the mechanism500. Additionally, if the lesion being treated has a small diameter, thepositioner wires will simply fold over as the inner cutter is moveddistally to open the cutter window 514. During the cutting operation,the positioner wires 510 will quickly spring back into the outer tubularcutter 506 since the tissue-penetrating member will act to maintaincontact with the material to be cut during the remainder of the cuttingoperation.

[0049] FIGS. 15-18 show a still further embodiment of the materialcapture device using a penetrating member and a cam surface. In FIG. 15,the penetrating member comprise a curved needle 260 which is fixedlysecured to the inner cutter 200 and biased against a cam surface 262.The curved needle 260 may be integrally formed with the inner cutter 200or otherwise attached such as by welding or other methods known in theart. As the inner cutter 200 is advanced, the cam surface 262 will guidethe needle 260 along a path outwardly to engage target material and thenit back towards the catheter body. As discussed previously, the needle260 need not move beyond the outer cutter 202, instead remaining evenwith the outer diameter of the outer cutter as the needle engagesmaterial. The inner cutter 200 may also include a material imagingdevice 264 such as an ultrasound transducer or optical fibers which willimage tissue when the window 204 is closed by the cutter. The opticalfibers may be used for optical coherence tomography or optical coherencereflectometry. A suitable ultrasound transducer or transducer array maybe found in commonly assigned, copending U.S. patent application Ser.No. 09/____ (Attorney Docket No. 18489-001000US), filed ______, the fulldisclosure of which is incorporated herein by reference.

[0050] FIGS. 16-18 shows various embodiments of the cam surface 262.FIG. 16 shows a perspective view of the cam surface 262 used in thedevice of FIG. 15. FIGS. 17 and 18 show a cam surface 270 which hasseparate tracks 272 and 274 which can guide the needle 260 alongdifferent needle paths when the needle is advanced and when the needleis retracted. The cam surface 270 has funneled portions 276 and 278 forguiding the needle into the respective tracks 272 and 274, depending onwhether the needle is being advanced or retracted.

[0051] Referring now to FIGS. 19-22, a telescoping cutting device usinga material capture device will be described in further detail. As shownin FIG. 19, the telescoping portion 300 in this embodiment of thecutting device extends outwardly from an aperture 302 on the catheterbody 304. The catheter body 304 may include a cutting blade 305 forshearing material drawn into the cutting device. It should beunderstood, of course, that the blade may be located in a variety ofpositions such as on the telescoping portion 300 of the device orlocated on both the telescoping portion and the catheter body. As shownin FIG. 19, the distal end 306 of the telescoping portion 300 ispreferably adapted to mount a soft, atraumatic distal tip (shown inphantom) to facilitate passage of the device through body lumens. Thetip may, in some embodiments, be integrally formed with the telescopingportion 300.

[0052] As seen in FIG. 19, the telescoping portion 300 is in a distalposition where one edge 307 of the telescoping portion is spaced apartfrom the catheter body and defines a cutting window 308. In someembodiments, the edge 307 may comprise a cutting blade while in otherembodiments the edge may be unsharpened, but pushing material into thecutting window. The cutting window 308 is preferably a directionalcutting window which may open towards one side of the catheter wherematerial may intrude to be cut off. A penetrating member 310 ispreferably rotatably mounted about a pivot pin 312 on the telescopingportion 300 to engage the material. It should be understood that someembodiments of the telescoping portion 300 may not include thepenetrating member 310. The penetrating member 310 is shown in FIG. 19to be in a first, tissue-engaging position. A tether or leash element314 is rotatably coupled to the penetrating member 310 and can be pulledproximally as indicated by arrow 316 to rotate the member into thetissue-engaging position. The tether 314 may be made of a variety ofmaterials such as stainless steel or a polymer like polyimide or afibrous material like Kevlar®.

[0053]FIG. 20 shows the telescoping portion 300 being retracted by adrive wire 318 as indicated by arrow 320. As one end of the penetratingmember 310 contacts abutment or deflection block 322, the penetratingmember 310 will begin to rotate as indicated by arrow 324. Furtherretraction of the telescoping portion 300 will cause the sharpened tip326 of the penetrating member 310 to be pushed within the boundaries ofthe catheter body. As seen in FIG. 21, the penetrating member 310 andtelescoping portion 300 may be substantially retracted into the catheterbody 304. The tether 314 has a bent portion 330 that allows thepenetrating member to rotated to the position shown in FIG. 22.Retraction of the penetrating member 310 into the catheter body as shownin FIG. 22 also functions to push tissue proximally into the catheterbody where it can be stored.

[0054] Referring now to FIGS. 23 and 24, a still further embodiment ofthe tissue capture device will be described. FIG. 23 shows a penetratingmember 340 that is rotatably mounted to the outer cutter 342, instead ofthe inner, slidable cutter 344 as shown in previous embodiments. Theinner cutter 344 can be reciprocated to cut off materials captured inthe window 346. The inner cutter 344 includes a pushing element 348 thatcontacts the penetrating member 340 to rotate the penetrating memberinto the target material and then return to the inside of the outercutter 342. The pushing element 348 traverses over the top of thesurface of the penetrating member and wipes off any tissue, directing itinto the catheter. The penetrating member 340 may be reset to itsstarting position by a variety of methods such as through the use of aleash element as described above or by using a bias element to create areturn force.

[0055] Referring now to FIG. 25, the present invention will furthercomprise kits including catheters 400, instructions for use 402, andpackages 404. Catheters 400 will generally be described above, and theinstruction for use (IFU) 402 will set forth any of the methodsdescribed above. Package 404 may be any conventional medical devicepackaging, including pouches, trays, boxes, tubes, or the like. Theinstructions for use 402 will usually be printed on a separate piece ofpaper, but may also be printed in whole or in part on a portion of thepackaging 404.

[0056] While all the above is a complete description of the preferredembodiments of the inventions, various alternatives, modifications, andequivalents may be used. For example, the cutters and material capturedevices may be oriented in a variety of angles on the catheter body. Asseen in FIGS. 26 and 27, the catheters 430 and 440 have cutters 432 and442 which are oriented perpendicularly or at other inclined angles to alongitudinal axis 450 of the catheter. A plurality of material capturedevices may be used with a single or a plurality of cutting blades.Additionally, as discussed above for FIG. 15, another embodiment of thedevice includes an ultrasound transducer 460 as shown in FIG. 28. Inplace of an ultrasonic transducer, the device may use one or moreoptical fibers for optical coherence tomography or optical coherencereflectometry. Although the foregoing invention has been described indetail for purposes of clarity of understanding, it will be obvious thatcertain modifications may be practiced within the scope of the appendedclaims.

What is claimed is:
 1. A catheter for removing material from a bodylumen, said catheter comprising: a catheter body having a proximal endand a distal end; a material capture device arranged on said catheterbody to engage said material; and a cutting element mounted near thedistal end of the catheter body to move between a first position and asecond position to cut said material while said material is engaged bysaid material capture device, wherein motion of the cutting elementurges the material capture device to draw cut material into the catheterbody.
 2. A catheter as in claim 1 wherein said catheter body comprises aproximal, flexible portion and a distal, rigid portion containing saidcutting element.
 3. A catheter as in claim 2 wherein said catheter bodycomprises a inner cutter mounted coaxially within said distal, rigidportion, said material capture device mounted on said inner cutter.
 4. Acatheter as in claim 2 wherein said catheter body comprises anatraumatic distal tip mounted on said distal, rigid portion.
 5. Acatheter as in claim 1 wherein: said material capture device is arrangedon said catheter body to advance along a path outwardly from thecatheter body into said material and then inwardly towards the catheterbody to tension said material; and said cutting element on said catheterbody moving between said first position and said second position to cutsaid material while in tension.
 6. A catheter as in claim 5 wherein saidpath comprises a radially curved path extending in an outward directionaway from the catheter body towards said material to be cut off.
 7. Acatheter as in claim 6 where in said material capture device movingalong said path does not exceed the outer diameter of the catheter body.8. A catheter as in claim 5 wherein said material capture device travelsin a slot on the catheter body to advance along said path.
 9. A catheteras in claim 5 wherein said material capture device travels in a grooveon the catheter body to advance along said path.
 10. A catheter as inclaim 5 wherein said material capture device comprises a bias element tourge said material capture device along said path.
 11. A catheter as inclaim 5 wherein said material capture device is configured to rotateabout a pivot pin to deploy said material capture device along saidpath.
 12. A catheter as in claim 1 wherein said material capture devicecomprises: a penetrating member pivotably mounted about a pin on saidcutting blade, said penetrating member movable between a first,tissue-engaging position and a second tissue-retracting position; and acam surface disposed on said catheter body to contact and rotate saidpenetrating member about said pivot point when said cutting blade isadvanced over the cam surface.
 13. A catheter as in claim 12 whereinsaid cam surface is configured to slidably contact a lower surface onsaid penetrating member to guide said penetrating member over anaccurate path as the cutting blade is advanced.
 14. A catheter as inclaim 13 wherein said cam surface includes a groove for mating with saidpenetrating member.
 15. A catheter as in claim 13 wherein said camsurface includes a first groove having a funneled opening and a secondgroove having a second funneled opening.
 16. A catheter as in claim 13wherein said penetrating member comprises a recess on said lower surfaceto facilitate positioning of said member over said cam surface.
 17. Acatheter as in claim 1 wherein said material capture device comprises: apenetrating member rotatably mounted on said cutting element; and anabutment disposed on said catheter body to engage one end of thepenetrable member and cause rotation of the penetrating member from afirst, open position to a second, closed position.
 18. A catheter as inclaim 17 further comprising a tether coupled to said penetrating memberto control positioning of the penetrating member.
 19. A catheter as inclaim 1 wherein said material capture device comprises a penetratingmember rotatably mounted on said catheter body and fixedly securedrelative to said slidable cutting element; a pushing element mounted onsaid cutting element to engage said penetrating member to move saidmember between a first position to a second tissue-engaging position.20. A catheter as in claim 1 wherein said material capture device isconfigured to be deployed from an aperture in the side wall of thecatheter body.
 21. A catheter as in claim 20 wherein said cuttingelement includes an material imaging device mounted to be in an imagingposition when said aperture is closed by said cutting element.
 22. Acatheter as in claim 1 wherein said cutting element includes a firstcutting blade having at least one penetrating point.
 23. A catheter asin claim 1 wherein said cutting element has a first cutting bladeopposed to a second cutting blade for removing said material.
 24. Acatheter as in claim 1 wherein said cutting element comprises a tubularinner cutter slidably mounted within an outer cutter of the catheterbody, said inner cutter coupled to a drive wire actuated by a user. 25.A catheter as in claim 1 wherein said material capture device extends anextension distance outward from the catheter body to engage material,said extension distance equal to the diameter of the catheter body. 26.A catheter as in claim 1 wherein said material capture device includes abarbed distal tip to retain material on the capture device.
 27. Acatheter as in claim 1 wherein said cutting element further comprises amaterial imaging device.
 28. A catheter as in claim 27 wherein saidmaterial imaging device comprises an ultrasound transducer array.
 29. Acatheter as in claim 1 wherein said material capture device comprisesmeans for penetrating said material.
 30. A catheter as in claim 29wherein said means for penetrating material comprises a curved needlebiased outwardly from the catheter body.
 31. A catheter as in claim 29wherein said means for penetrating material comprises a penetratingmember rotatably mounted about a pivot pin on said cutting element. 32.A catheter as in claim 29 wherein said means for penetrating material isconfigured to engage a raised portion on said catheter body to move saidmeans to engage material and then retract material into the catheterbody.
 33. A catheter as in claim 32 wherein said raised portioncomprises a cam surface having a plurality of tracks, wherein each trackhas a funneled entrance to guide said penetrating member therein.
 34. Acatheter for removing material from the wall of a body lumen, saidcatheter comprising: a catheter body having a proximal end and a distalend; a side aperture on the catheter body; a cutting blade adapted toadvance past the aperture to sever material which intrudes through theaperture; and a penetration member mounted to extend through theaperture to penetrate material in advance of the cutting blade and todraw material into the catheter body as the cutting blade is advancedpast the aperture.
 35. A catheter as in claim 34 further comprising acam surface mounted on said catheter body, said cam surface having asurface configured to guide said penetration member into said materialwhen said blade is advanced.
 36. A catheter for removing material from abody lumen, said catheter comprising: a catheter body having a proximalend and a distal end; a material capture device arranged on saidcatheter body to advance along a path radially outwardly from thecatheter body into said material and then inwardly towards the catheterbody to tension said material; and a cutting element on said catheterbody moving between a first position and a second position to cut saidmaterial while said material is in tension.
 37. A catheter for removingmaterial from a body lumen, said catheter comprising: a catheter bodyhaving a proximal end, a distal end, and an aperture; a slidable,telescoping portion on said catheter body configured to extend outwardlyfrom said aperture on the catheter body, said telescoping portion havinga first open position leaving a gap between one edge of said portion andsaid catheter body to define a cutter window in which material mayintrude to be engaged and having a second closed position wherein saidcutting blade is positioned to cut off said material.
 38. A catheter asin claim 37 wherein said gap defines a side-opening cutter window.
 39. Acatheter as in claim 37 wherein said aperture comprises a forwardfacing, distal aperture on the catheter body.
 40. A catheter as in claim37 further comprising a material capture device mounted on saidtelescoping portion, said portion moving between a first position and asecond position to cut said material while said material is engaged bysaid material capture device, wherein motion of the telescoping portionurges the material capture device to draw cut material into the catheterbody.
 41. A catheter as in claim 40 wherein said material capture deviceis rotatably mounted to said telescoping portion and configured toengage a raised portion on said catheter body to rotate said materialcapture device to engage material and then draw material into thecatheter body.
 42. A method for excising occlusive material from withina body lumen, said method comprising: capturing said occlusive materialwith a material capture device on a catheter body; drawing said deviceradially inwardly towards the catheter body to tension the material; andadvancing a blade through the tensioned material to sever said materialfrom the body lumen.
 43. A method as in claim 42 wherein said engagingof said occlusive material comprises extending said material capturedevice from said catheter body in a radially outward direction.
 44. Amethod as in claim 43 wherein said material capture device does notextend beyond the outer diameter of the catheter body when engaging saidmaterial.
 45. A method as in claim 42 wherein said engaging of saidocclusive material comprises penetrating said material with saidmaterial capture device.
 46. A method as in claim 42 wherein saidengaging of occlusive material comprises radially extending saidmaterial capture device outward from an aperture on the catheter body.47. A method as in claim 46 wherein said engaging of said occlusivematerial comprises guiding said material capture device against a raisedportion on the catheter body to direct said capture device into saidmaterial.
 48. A method as in claim 46 wherein said engaging of saidocclusive material comprises advancing said cutting blade to engage apushing element against said material capture device mounted on thecatheter body.
 49. A method as in claim 46 wherein said engaging of saidocclusive material comprises penetrating said material in advance of theblade and said drawing of said device into the catheter body occurs asthe cutting blade is advanced past the aperture.
 50. A method as inclaim 46 further comprising imaging said material prior to cutting saidmaterial, wherein said imaging occurs when said aperture is closed bysaid cutting blade.
 51. A method as in claim 42 wherein said drawing ofthe device comprises moving said material capture device radiallytowards said catheter body while said material capture device remains incontact with said material.
 52. A method as in claim 51 wherein saiddrawing of said material capture device occurs when said cutting elementis advanced, said cutting element pushing against said material capturedevice and biasing it into the catheter body.
 53. A method as in claim51 wherein drawing of said material capture device comprises positioningsaid material capture device against a raised portion on the catheterbody to guide said device with the material into the catheter body. 54.A method as in claim 42 wherein said engaging and tensioning of materialare performed through a single motion by the user.
 55. A method forremoving material from a body lumen, said method comprising: positioninga catheter within the lumen; extending a distal portion of the catheterforwardly to open an aperture, wherein material is invaginated into theaperture; and closing the distal portion of the catheter to close theaperture and sever the invaginated material.
 56. A method as in claim55, wherein the body lumen is a blood vessel and the material isatheromatous material.
 57. A method as in claim 55, further comprisingpenetrating the tissue with a material capture device and drawing thecaptured material into the aperture with the device as the distalportion of the catheter body is closed.
 58. A kit comprising: a catheterhaving a material capture device and a cutting element; instructions foruse in removing material from a body lumen comprising engaging saidmaterial with a material capture device and tensioning said materialtowards the catheter while cutting said occlusive material with acutting element; and a package adapted to contain the device and theinstructions for use.